—The types chiefly used in packing house work are simplex and duplex reciprocating, centrifugal single and multi-stage operated by motor or steam turbine directly attached to the motive power, also power pumps of triplex type and rotary or impeller pumps for fats and oils. There are endless varieties of each type.

Pumps for Brine.

—For brine pumping chiefly reciprocating and direct connected horizontally set motor driven centrifugal pumps of one or more stages are used. At times power operated triplex pumps are used but the most satisfactory are the second named.

Pumping brine for refrigerating purposes is a never ending process since it must be constantly performed. The common practice of an open brine tank with submerged coils is being fast superseded by the use of shell and tube type closed coolers which superseded double pipe coolers. The use of either the latter two types enables the operator to take advantage of hydraulic head by installing a balanced system described in this work which very greatly reduces the power necessary to exert to pump brine. The friction in an eight to twelve pass brine cooler is from ten to fifteen pounds, and this with the pipe friction on a balanced system will total to perhaps thirty pounds on large systems, but less than the ordinary open system—depending upon the building height.

Water Supply.

—The water demand for packing house operation is quite an important element in relation to steam consumption. The quantity required for ammonia condensing, steam condensing (if done), and for plant purposes, washing, etc., is, in the aggregate, quite a large amount. For example: For ammonia condensing, from 1¹⁄₄ to 1¹⁄₂ gallons per minute is required per ton of refrigeration developed; for steam condensing for steam engine from 32 to 40 pounds per pound of steam condensed; for boiler operation about four gallons per horse power per hour; for plant purposes from 250 to 3,000 gallons or more per hour, depending upon the size of plant and its intelligent use. It will be readily seen that those quantities will mount in power consumption if the head or pressure pumped against is high.

Pumps for Wells.

—Water pumped from wells is usually pumped by one of four methods:

For small plants where one or two wells will supply the water, the first named pump is usually used owing to cheapness of cost for installing and particularly if the water rises in the well to a height reachable by a suction type pump, viz: 23 to 25 feet. Power operated suction pumps are also available for this service. If the water be too low for the above named type to handle, deep well pumps with steam head serve pretty well and usually cost less than air pumped wells.